Electrical device



Oct. 27, 1964 R. WEGENER ELECTRICAL DEVICE Filed March 9, 1962 Jnvenlor: Rokf \Oegener United States Patent "ice 3,154,755 ELECTRICALDEVICE Rolf Wegener, Bielefeld, Germany, assignor to TelefunkenPatentverwertungs-G.m.b.I-I., Ulrn (Danube), Germany Filed Mar. 9, 1962,Ser. No. 178,719

Claims priority, application Germany Mar. 14, 1%1

1 Claim. (iii. 334-43) The present invention relates to ultrahighfrequency (UHF) devices, and, more particularly, to such devices whereinthe inductances of oscillator circuits associated therewith are disposedin sealed chambers and may be tuned for matching purposes.

Matching devices of the above-mentioned type often contain inductanceelements which are arcuate or in the shape of bows and which arearranged in sealed chambers and used for tuning purposes. In order toprovide for tuning, the effective length of this how member may beadjusted by means of a short circuit slide bar which is movable betweena wall of the sealed chamber and the bow member. Due to the fact thatthe waveguide tubes which are used have inductances and capacitanceswhich do not permit an exact initial determination of the resonantfrequency of the bow, it has been the custom to carry out matching bybending a conductor which is disposed between the bow member and acontact on the waveguide tube.

However, such an arrangement presents a disadvantage because bendingthis conductor changes not only the total inductance, but also theinductance and capacitance of the bow itself. They are changed to anextent which cannot be previously determined and which cannot beproduced, and therefore the matching is impaired. Furthermore, suchmatching may not be carried out exteriorly of the device and the devicemust be opened in order to bend the conductor. Therefore, the known typearrangements presented great difficulties in the mass production ofthese UHF devices.

With these defects of the prior art in mind, it is a main object of thepresent invention to provide a matching arrangement for UHF deviceswhich may be adjusted exteriorly and without opening the device.

Another object of the invention is to provide means for adjusting theinductance of the conductor in a simple and accurate manner.

These objects and others ancillary thereto are accomplished according topreferred embodiments of the invention wherein the connecting line whichis connected between the bow member and the waveguide tube contact, oranother suitable stationary contact, is so dimensioned that it may notbe deformed at all or only with difficulty by outside influences. Thisconnecting line or conductor is arcuate and defines a portion of acircle. An electrically conductive body or core is movably positionedwithin this are whereby the inductance of the conductor may beadjustably and selectively varied.

Additional objects and advantages of the present invention will becomeapparent upon consideration of the following description when taken inconjunction with the accompanying drawing in which the single figure isa perspective view illustrating the bow and the conductor constructed ofone piece, with the conductor bent away from the bow.

With more particular reference to the drawing, an ultrahigh frequencyarrangement 1 is provided with walls and the like in order to define aplurality of chambers 2 which are independent and separate from oneanother, but which may be coupled together. To form the oscillatorcircuits, Lecher wires are arranged in these chambers. The Lecher wiresare formed with one conductor 3,154,755 Patented Oct. 27, 1964 beingdefined by the wall 3 and the other conductor being formed by the bowmember 4. One end of this bow member may be conductively connected withthe bottom and/ or with the walls of the chamber. The other end of thebow member is connected to a conductor 5 which is connected to a contactor terminal 7 of a waveguide tube 8, and may be connected directlythereto or by means of a capacitor 6.

Also, a trimmer capacitor 9 may be used as an anchoring point for thefree end of conductor 5 and this capacitor is arranged at this point formatching purposes. In order to tune the oscillator circuit of thechamber, a short circuit slide bar it? is arranged between theconductors of the Lecher wire, that is, between the bow 4 and the wall3. The slide bar is connected to a shaft 11 and is movable therewith.The shaft 11 preferably extends through all of the chambers and may beused in an advantageous manner for also tuning the Lecher wires and/oroscillator circuits arranged in the other chambers.

In order to compensate for deviations of the oscillator circuit from thedesired values of resonant frequency, the connecting line or conductor 5is formed as an arc of a circle or as a spiral between the free end ofbow member 4 and the terminal 7 of the waveguide tube 8. Thesedeviations are caused by operating or working tolerances as well as theinherent inductances and inherent capacitances of the waveguide tube andits conductors. Within the are formed by conductor 5, a threaded body 12is axially displaceably mounted, this body being formed of a conductivematerial. Preferably, the body 12 is silver-plated. Due to thesefactors, the inductance of conductor 5 is varied in order to be closerto or at the point which matches the resonant frequency.

In order to provide for uniform manufacture of the device with valueswhich may be reproduced for all devices of the same type, the conductor5 is constructed to be self-holding so that it cannot be displaced ordeformed by smaller forces, e.g., during the matching operation.Preferably, conductor 5 is constructed of one piece with bow member 4,as, for example, by punching. Thus, the conductor 5 when mounted withthe other components defines the arc of a circle which arc is especiallydetermined for this part. The conductor 5 may be constructed ofdifierent length depending upon the use of the bow member in thedifferent chambers of such a tuning arrangement and it may be shaped tobe the arc of a circle or in the shape of a spiral.

The screw body 12 may be arranged to be displaceable either through thebottom plate of the chamber, in which case it may be done externally, orit may be done internally from the inside of the chamber after removingthe cover. Preferably, this body 12 is mounted so that it has noconductive connection with the casing or chassis although such aconductive connection is permissible.

As an example the bow member 4 and the conductor 5 may have a thicknessof 1 mm. The width of the bow member 4 may be 3 mm. and that of theconductor 1.5 mm. in this example.

The frequency range, in which the device is to be used may be from 450to 1000 mcs.

it will be understood that the above description of the presentinvention is susceptible to various modifications, changes, andadaptations, and the same are intended to be comprehended within themeaning and range of equivalents of the appended claim.

What is claimed is:

In a matching device for ultra high frequency devices in whichoscillator circuits contained in chambers are formed by Lecher wires ofa chamber wall and a bow, a short circuit slide bar movable between suchwall and the bow for tuning purposes and in which a connecting linebetween the bow and a connecting contact pertaining thereto may beinfluenced for changing the total inductivity of the bow, theimprovement wherein the connecting line and the bow are one piece, thebow is disposed in a plane, the connecting line is displaced from theplane of the bow and forms only part of an arc and an electricallyconductive core is disposed Within the arc of said connecting line, saidelectrically conductive core including a metal screw threaded from theexterior through a wall of the chamber into the interior of the chamber.

References Cited in the file of this patent UNITED STATES PATENTS WallinMar.

Osborn Nov.

Murakami et a1. Apr

Gossard July Reiches Jan.

